Officers were called to the North Parade area in Skegness at 8am this morning.
The body of a man, who has yet to be identified, had been discovered in the area.
A spokesman for Lincolnshire Police said the exact location is still to be confirmed but the death is being treated as unexplained.
Anyone with information that could help with the enquiry is asked to contact police by calling 101, quoting reference number 104 of 21/07/2018.
Anternatively call independent charity Crimestoppers, anonymously, on 0800 555 111 or visit crimestoppers-uk.org.